Numerous compositions have been proposed as organopolysiloxane compositions which form cured coating films at room temperature. For example, a composition consisting of a hydroxy group-containing organopolysiloxane resin, organoalkoxysilanes and an organic solvent has been proposed in Japanese Patent Application Kokai No. 51-148749. However, cured coating films produced from a composition consisting chiefly of this type of organopolysiloxane resin are inferior in terms of wear resistance, and are unsuitable for some applications.
Furthermore, polycarbonates and polyarylates are known as coating agents, and are widely used in optical applications, etc. For example, a medical material containing a polycarbonate with cross-linkable silyl groups as an active ingredient has been proposed (see Japanese Patent Application Kokai No. 58-109062). However, cured coating films produced from compositions containing a polycarbonate with cross-linkable silyl groups have inferior water-repellent properties, and, therefore, cannot be used in some applications.